diff --git a/src/PDF/Content/Text.hs b/src/PDF/Content/Text.hs
index 9826b88..16f0493 100644
--- a/src/PDF/Content/Text.hs
+++ b/src/PDF/Content/Text.hs
@@ -16,7 +16,7 @@ import Control.Monad.Fail (MonadFail(..))
 import Control.Monad.Reader (MonadReader(..), ReaderT, asks, runReaderT)
 import Control.Monad.State (MonadState(..), StateT, evalStateT)
 import Data.Map ((!))
-import qualified Data.Map as Map (empty, fromList, singleton)
+import qualified Data.Map as Map (empty, singleton)
 import Data.Text (Text, breakOn)
 import qualified Data.Text as Text (drop)
 import PDF.Box (Box(..))
@@ -46,7 +46,7 @@ decodeString input = do
 
 data Chunks = Chunks
 
-instance (MonadReader FontSet m, MonadFail m) => Box m Chunks Content (Indexed Text) where
+instance MonadFail m => Box (ReaderT FontSet m) Chunks Content (Indexed Text) where
   r Chunks content = do
     fontSet <- ask
     renderText fontSet content